Patent US2494497A successfully refreshed from Google Patents.
US2494497A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Educational device
Assignee: Individual
•
Filing: 1946-08-09
•
Granted: 1950-01-10
•
Expires: 1966-08-09
Abstract
No abstract record available.
Inventors
- 👤 Buel L Trapnell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:56
CPC Classifications
G; G09; G09B; G09B19/00; G09B19/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US422612A
Cited
US677952A
Cited
US805365A
Cited
US889515A
Cited
US971185A
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US1151279A
Cited
US1396379A
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US1329850A
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FR525040A
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US1471437A
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US1483916A
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US1594376A
Cited
US1578554A
Cited
US1694405A
Cited
US1696988A
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US1649578A
Cited
US1950072A
Cited
US2014675A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-01-09 | 1953-07-11 | 1954-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-01-09 | 1957-07-11 | 1958-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-01-09 | 1961-07-11 | 1962-01-10 | $7700.00 | Window Closed / Lapsed |